RESUMO
Insulin secretion by pancreatic islet ß-cells is regulated by glucose levels and is accompanied by proton generation. The voltage-gated proton channel Hv1 is present in pancreatic ß-cells and extremely selective for protons. However, whether Hv1 is involved in insulin secretion is unclear. Here we demonstrate that Hv1 promotes insulin secretion of pancreatic ß-cells and glucose homeostasis. Hv1-deficient mice displayed hyperglycemia and glucose intolerance because of reduced insulin secretion but retained normal peripheral insulin sensitivity. Moreover, Hv1 loss contributed much more to severe glucose intolerance as the mice got older. Islets of Hv1-deficient and heterozygous mice were markedly deficient in glucose- and K+-induced insulin secretion. In perifusion assays, Hv1 deletion dramatically reduced the first and second phase of glucose-stimulated insulin secretion. Islet insulin and proinsulin content was reduced, and histological analysis of pancreas slices revealed an accompanying modest reduction of ß-cell mass in Hv1 knockout mice. EM observations also indicated a reduction in insulin granule size, but not granule number or granule docking, in Hv1-deficient mice. Mechanistically, Hv1 loss limited the capacity for glucose-induced membrane depolarization, accompanied by a reduced ability of glucose to raise Ca2+ levels in islets, as evidenced by decreased durations of individual calcium oscillations. Moreover, Hv1 expression was significantly reduced in pancreatic ß-cells from streptozotocin-induced diabetic mice, indicating that Hv1 deficiency is associated with ß-cell dysfunction and diabetes. We conclude that Hv1 regulates insulin secretion and glucose homeostasis through a mechanism that depends on intracellular Ca2+ levels and membrane depolarization.
Assuntos
Intolerância à Glucose/complicações , Intolerância à Glucose/metabolismo , Hiperglicemia/complicações , Hiperglicemia/metabolismo , Secreção de Insulina , Canais Iônicos/metabolismo , Envelhecimento/patologia , Animais , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Tamanho Celular , Grânulos Citoplasmáticos/metabolismo , Grânulos Citoplasmáticos/ultraestrutura , Citosol/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Regulação para Baixo/efeitos dos fármacos , Deleção de Genes , Glucose/farmacologia , Concentração de Íons de Hidrogênio , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Células Secretoras de Insulina/ultraestrutura , Canais Iônicos/deficiência , Canais Iônicos/genética , Potenciais da Membrana , Camundongos Endogâmicos C57BL , Camundongos Knockout , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
The spatiotemporal generation of nitric oxide (NO), a versatile endogenous messenger, is precisely controlled. Despite its therapeutic potential for a wide range of diseases, NO-based therapies are limited clinically due to a lack of effective strategies for precisely delivering NO to a specific site. In the present study, we developed a novel NO delivery system via modification of an enzyme-prodrug pair of galactosidase-galactosyl-NONOate using a 'bump-and-hole' strategy. Precise delivery to targeted tissues was clearly demonstrated by an in vivo near-infrared imaging assay. The therapeutic potential was evaluated in both rat hindlimb ischemia and mouse acute kidney injury models. Targeted delivery of NO clearly enhanced its therapeutic efficacy in tissue repair and function recovery and abolished side effects due to the systemic release of NO. The developed protocol holds broad applicability in the targeted delivery of important gaseous signaling molecules and offers a potent tool for the investigation of relevant molecular mechanisms.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Óxido Nítrico/administração & dosagem , Óxido Nítrico/metabolismo , Animais , Compostos Azo , Galactosidases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Óxido Nítrico/fisiologia , Pró-Fármacos , Ratos , Ratos Sprague-Dawley , beta-Galactosidase/metabolismo , beta-Galactosidase/fisiologiaRESUMO
Glucocorticoid receptors (GRs) exert actions on the hippocampus that are important for memory formation. There are correlations between vascular dysfunctions and GR-related gene expression. Both vascular dysfunction and GR gene expression decline occur during the ageing process. Therefore, hypotensors, which have effects on improving vascular dysfunction, may be able to ameliorate GR gene expression decline in ageing mice and improve ageing-mediated memory deficits. In this study, we hypothesized that hypotensors could alleviate the decline of GR gene expression and ameliorate age-induced learning and memory deficits in a D-gal-induced ageing mice model. In line with our hypothesis, we found that chronic D-gal treatment decreased GR and DCX expression in the hippocampus, leading to learning and memory deficits. Amlodipine (AM) and puerarin (PU) treatment improved GR gene expression decline in the hippocampus and ameliorated the learning and memory deficits of D-gal-treated mice. These changes correlated with enhanced DCX expression and brain-derived neurotrophic factor (BDNF) expression in the hippocampus. Furthermore, PU treatment conveyed better effects than AM treatment, but combination therapy did not enhance the effects on improving GR expression. However, we did not find evidence of these changes in non-D-gal-treated mice that lacked GR gene expression decline. These results suggest that AM and PU could improve D-gal-induced behavioural deficits in correlation with GR gene expression.
Assuntos
Anlodipino/administração & dosagem , Giro Denteado/metabolismo , Galactose/toxicidade , Isoflavonas/administração & dosagem , Aprendizagem em Labirinto/fisiologia , Receptores de Glucocorticoides/biossíntese , Envelhecimento/efeitos dos fármacos , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Giro Denteado/efeitos dos fármacos , Giro Denteado/patologia , Proteína Duplacortina , Quimioterapia Combinada , Feminino , Expressão Gênica , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Neurogênese/efeitos dos fármacos , Neurogênese/fisiologia , Receptores de Glucocorticoides/genética , Vasodilatadores/administração & dosagemRESUMO
Low cell retention and engraftment after transplantation limit the successful application of stem cell therapy for AKI. Engineered microenvironments consisting of a hydrogel matrix and growth factors have been increasingly successful in controlling stem cell fate by mimicking native stem cell niche components. Here, we synthesized a bioactive hydrogel by immobilizing the C domain peptide of IGF-1 (IGF-1C) on chitosan, and we hypothesized that this hydrogel could provide a favorable niche for adipose-derived mesenchymal stem cells (ADSCs) and thereby enhance cell survival in an AKI model. In vitro studies demonstrated that compared with no hydrogel or chitosan hydrogel only, the chitosan-IGF-1C hydrogel increased cell viability through paracrine effects. In vivo, cotransplantation of the chitosan-IGF-1C hydrogel and ADSCs in ischemic kidneys ameliorated renal function, likely by the observed promotion of stem cell survival and angiogenesis, as visualized by bioluminescence imaging and attenuation of fibrosis. In conclusion, IGF-1C immobilized on a chitosan hydrogel provides an artificial microenvironment for ADSCs and may be a promising therapeutic approach for AKI.
Assuntos
Injúria Renal Aguda/terapia , Fator de Crescimento Insulin-Like I/administração & dosagem , Transplante de Células-Tronco Mesenquimais , Tecido Adiposo/citologia , Animais , Quitosana , Terapia Combinada , Hidrogel de Polietilenoglicol-Dimetacrilato , CamundongosRESUMO
BACKGROUND: Xian-Fang-Huo-Ming-Yin (XFHM), a traditional herbal formula, has been used to treat sores and carbuncles for hundreds of years in Asia. Nowadays, its clinical effects in treatment of rheumatoid arthritis (RA) have been validated. In this study, we want to study its possible molecular mechanisms of regulating the differentiation of lymphocytes and production of pro-inflammatory cytokines in collagen-induced arthritis (CIA) mice for RA treatment. METHODS: A high performance liquid chromatography-electrospray ionization/mass spectrometer (HPLC-ESI/MSn) system was used to analyze the constituents of XFHM granules. An arthritics mouse model was induced by collagen and leflunomide (LEF) was used as a positive control medicine. Pathological changes at the metatarsophalangeal joint were studied through Safranin O and immunohistochemical staining. The differentiation of T, B and NK cells was examined by flow cytometry and pro-inflammatory cytokines were assayed using an Inflammation Antibody Array assay. The expression of key molecules of the nuclear factor κB (NF-κB) and Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathways in spleen were studied by western-blot analysis. RESULTS: In our study. 21 different dominant chemical constituents were identified in XFHM. Treatment with XFHM suppressed the pathological changes in arthrosis of CIA. Additionally, XFHM down-regulated the proliferation and differentiation of CD3+ T cells and CD3-CD19+ B cells significantly. However, XFHM had no significant effect on CD3-NK1.1+ NK cells. Further study showed that the production of pro-inflammatory cytokines had been suppressed by inhibiting the activation of NF-κB and JAK/STAT signaling. CONCLUSIONS: XFHM can regulate and maintain the immunologic balance of lymphocytic immunity and inhibit the production of pro-inflammatory cytokines, thus suppressing the pathological changes of RA. Therefore, XFHM may be used as an application of traditional medicine against RA in modern complementary and alternative therapeutics.
Assuntos
Artrite/tratamento farmacológico , Diferenciação Celular , Citocinas/imunologia , Medicamentos de Ervas Chinesas/administração & dosagem , Linfócitos/citologia , Animais , Artrite/genética , Artrite/imunologia , Artrite/fisiopatologia , Colágeno/efeitos adversos , Citocinas/genética , Modelos Animais de Doenças , Humanos , Janus Quinases/genética , Janus Quinases/imunologia , Linfócitos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos DBA , NF-kappa B/genética , NF-kappa B/imunologiaRESUMO
BACKGROUND/AIMS: Impaired diabetes wound healing can often lead to serious complications and remains a major health concern due to the lack of effective therapeutic approaches. Compromised angiogenesis, disrupted growth factor and cytokine activity are all attributable to diabetic wound healing impairment. The skin-derived precursors (SKPs) have been shown to differentiate into vascular and nerve cells, both of which are crucial components for wound repair. Given their easy accessibility and multipotency, the SKPs were proposed as an ideal therapeutic candidate for diabetic wound healing. Since the efficacy of cell therapy is limited by poor cell survival, collagen sponge was employed for better SKPs delivery. METHODS: SKPs were isolated and transplanted directly to the wound areas of diabetic mice in the absence and presence of collagen sponge. The effects of SKPs and/or collagen sponge on diabetic wound healing were examined histologically as well as immunostaining of isolectin and α-SMA. Mechanisms via which the SKPs facilitate wound healing were then investigated by transplanting SKPs that have been pre-labelled with a fluorescence dye, Dil. Expression patterns of Dil and an SKP marker, nestin, was also examined. RESULTS AND CONCLUSION: Accelerated wound healing and enhanced local capillary regeneration could be observed 14 days after skin ablation from both SKPs and collagen sponge co-transplanted and collagen sponge only groups. Subsequent analyses further revealed superior pro-angiogenic effects from the SKP and collagen sponge co-delivered group, which are mainly attributable to in vivo transdifferentation and paracrine signalling of the SKPs.
Assuntos
Colágeno/farmacologia , Regeneração/fisiologia , Dermatopatias/terapia , Pele/metabolismo , Transplante de Células-Tronco , Cicatrização/efeitos dos fármacos , Animais , Capilares/fisiologia , Transdiferenciação Celular/efeitos dos fármacos , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Comunicação Parácrina/efeitos dos fármacos , Pele/patologia , Células-Tronco/citologia , Células-Tronco/metabolismoRESUMO
The voltage-gated proton channel Hv1 is a potent acid extruder that participates in the extrusion of the intracellular acid. Here, we showed for the first time, Hv1 is highly expressed in mouse and human pancreatic islet ß-cells, as well as ß-cell lines. Imaging studies demonstrated that Hv1 resides in insulin-containing granules in ß-cells. Knockdown of Hv1 with RNA interference significantly reduces glucose- and K(+)-induced insulin secretion in isolated islets and INS-1 (832/13) ß-cells and has an impairment on glucose- and K(+)-induced intracellular Ca(2+) homeostasis. Our data demonstrated that the expression of Hv1 in pancreatic islet ß-cells regulates insulin secretion through regulating Ca(2+) homeostasis.
Assuntos
Cálcio/metabolismo , Glucose/metabolismo , Células Secretoras de Insulina/fisiologia , Insulina/metabolismo , Ativação do Canal Iônico/fisiologia , Canais Iônicos/fisiologia , Animais , Linhagem Celular , Células Cultivadas , Humanos , Secreção de Insulina , CamundongosRESUMO
Tumors use a wide array of immunosuppressive strategies, such as reducing the longevity and survival of dendritic cells (DCs), to diminish immune responses and limit the effect of immunotherapy. In this study, we found that tumors upregulate the expression of multiple microRNAs (miRNAs), such as miR-16-1, miR-22, miR-155, and miR-503. These tumor-associated miRNAs influenced the survival and longevity of DCs by affecting the expression of multiple molecules that are associated with apoptotic signaling pathways. Specifically, miR-22 targeted YWHAZ to interrupt the PI3K/Akt and MAPK signaling pathways, and miR-503 downregulated Bcl2 expression. The result of the increased expression of miR-22 and miR-503 in the tumor-associated DCs was their reduced survival and longevity. Thus, tumor-associated miRNAs can target multiple intracellular signaling molecules to cause the apoptosis of DCs in the tumor environment. Use of miR-22 and miR-503 as inhibitors may therefore represent a new strategy to improve DC-based immunotherapies against tumors.
Assuntos
Proteínas 14-3-3/genética , Sobrevivência Celular/genética , Células Dendríticas/metabolismo , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transdução de Sinais/imunologia , Proteínas 14-3-3/imunologia , Animais , Apoptose/genética , Apoptose/imunologia , Linhagem Celular Tumoral , Sobrevivência Celular/imunologia , Células Dendríticas/imunologia , Células Dendríticas/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/imunologia , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/imunologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/imunologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/imunologia , Proteínas Proto-Oncogênicas c-bcl-2/imunologia , RNA Interferente Pequeno/genética , TransfecçãoRESUMO
In our previous work, we showed for the first time that the voltage-gated proton channel Hv1 is specifically expressed in highly metastatic human breast tumor tissues and cell lines. However, the contribution of Hv1 to breast carcinogenesis is not well known. In this study, we showed that Hv1 expression was significantly correlated with the tumor size (p = 0.001), tumor classification (p = 0.000), lymph node status (p = 0.000), clinical stage (p = 0.000), and Her-2 status (p = 0.045). High Hv1 expression was associated significantly with shorter overall (p = 0.000) and recurrence-free survival (p = 0.000). In vitro, knockdown of Hv1 expression in the highly metastatic MDA-MB-231 cells decreased the cell proliferation and invasiveness, inhibited the cell proton secretion and intracellular pH recovery, and blocked the cell capacity of acidifying extracellular milieu. Furthermore, the gelatinase activity in MDA-MB-231 cells that suppressed Hv1 was reduced. In vivo, the breast tumor size of the implantation of the MDA-MB-231 xenografts in nude mice that were knocked down by Hv1 was dramatically smaller than that in the control groups. The results demonstrated that the inhibition of Hv1 function via knockdown of Hv1 expression can effectively retard the cancer growth and suppress the cancer metastasis by the decrease of proton extrusion and the down-regulation of gelatinase activity. Based on these results, we came to the conclusion that Hv1 is a potential biomarker for prognosis of breast cancer and a potential target for anticancer drugs in breast cancer therapy.
Assuntos
Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Canais Iônicos/biossíntese , Idoso , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Proliferação de Células , Progressão da Doença , Feminino , Humanos , Concentração de Íons de Hidrogênio , Lentivirus/genética , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Metástase Neoplásica , Transplante de Neoplasias , Prognóstico , Resultado do TratamentoRESUMO
BACKGROUND: Despite increasing attention on the role of bone marrow derived stem cells in repair or rejuvenation of tissues and organs, cellular mechanisms of such cell-based therapy remain poorly understood. METHODS: We reconstituted hematopoiesis in recipient C57BL/6J mice by transplanting syngeneic GFP(+) bone marrow (BM) cells. Subsequently, the recipients received subcutaneous injection of granulocyte-colony stimulating factor (G-CSF) and were subjected to acute renal ischemic injury. Flow cytometry and immunostaining were performed at various time points to assess engraftment and phenotype of BM derived stem cells. RESULTS: Administration of G-CSF increased the release of BM derived stem cells into circulation and enhanced the ensuing recruitment of BM derived stem cells into injured kidney. During the second month post injury, migrated BM derived stem cells lost hematopoietic phenotype (CD45) but maintained the expression of other markers (Sca-1, CD133 and CD44), suggesting their potential of transdifferentiation into renal stem cells. Moreover, G-CSF treatment enhanced the phenotypic conversion. CONCLUSION: Our work depicted a time-course dependent transition of phenotypic characteristics of BM derived stem cells, demonstrated the existence of BM derived stem cells in damaged kidney and revealed the effects of G-CSF on cell transdifferentiation.
Assuntos
Injúria Renal Aguda/patologia , Células-Tronco Hematopoéticas/fisiologia , Animais , Transplante de Medula Óssea , Transdiferenciação Celular , Modelos Animais de Doenças , Feminino , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células-Tronco Hematopoéticas/metabolismo , Rim/irrigação sanguínea , Rim/patologia , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Traumatismo por Reperfusão/patologia , Fatores de TempoRESUMO
Toll-like receptors (TLRs) are important initiators in innate immune responses against pathogenic microbes such as viruses, intracellular bacteria or parasites. Although the innate immune system is designed to fight infectious pathogens, excessive activation of TLR signaling may lead to unwarranted inflammation with hazardous outcomes. Mechanisms of restraining excessive inflammation and controlling homeostasis for innate immunity are the focus of intense study. Here we showed that LRRC33, a novel member of leucine-rich repeat (LRR) protein family, plays a critical role in desensitizing TLR signaling. LRRC33 is TLR homolog that contains 17 putative LRRs in the extracellular region but lacks a cytoplasmic Toll/IL-1 receptor (TIR) domain. Expression of LRRC33 appears to be ubiquitous with high level of expression found in bone marrow, thymus, liver, lung, intestine and spleen. The LRRs of LRRC33 is required for the interaction with TLR and its inhibitory effect on NF-κB and AP-1 activation as well as cytokine production. Our study sheds new insight into the TLR signaling and inflammatory response in development and human diseases.
Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/fisiologia , Imunidade Inata , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Proteínas/química , Proteínas/fisiologia , Receptores Toll-Like/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Células HEK293 , Humanos , Imunidade Inata/genética , Proteínas de Ligação a TGF-beta Latente , Proteínas de Repetições Ricas em Leucina , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , NF-kappa B/genética , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Proteínas/genética , Proteínas Modificadoras da Atividade de Receptores , Sequências Repetitivas de Aminoácidos/genética , Sequências Repetitivas de Aminoácidos/imunologia , Receptores Toll-Like/genética , Receptores Toll-Like/fisiologia , Células U937RESUMO
BACKGROUND: Bone marrow (BM) stem cells have been reported to contribute to tissue repair after kidney injury model. However, there is no direct evidence so far that BM cells can trans-differentiate into renal stem cells. METHODS: To investigate whether BM stem cells contribute to repopulate the renal stem cell pool, we transplanted BM cells from transgenic mice, expressing enhanced green fluorescent protein (EGFP) into wild-type irradiated recipients. Following hematological reconstitution and ischemia-reperfusion (I/R), Sca-1 and c-Kit positive renal stem cells in kidney were evaluated by immunostaining and flow cytometry analysis. Moreover, granulocyte colony stimulating factor (G-CSF) was administrated to further explore if G-CSF can mobilize BM cells and enhance trans-differentiation efficiency of BM cells into renal stem cells. RESULTS: BM-derived cells can contribute to the Sca-1(+) or c-Kit(+) renal progenitor cells population, although most renal stem cells came from indigenous cells. Furthermore, G-CSF administration nearly doubled the frequency of Sca-1+ BM-derived renal stem cells and increased capillary density of I/R injured kidneys. CONCLUSIONS: These findings indicate that BM derived stem cells can give rise to cells that share properties of renal resident stem cell. Moreover, G-CSF mobilization can enhance this effect.
Assuntos
Injúria Renal Aguda/patologia , Injúria Renal Aguda/cirurgia , Células da Medula Óssea/patologia , Transplante de Medula Óssea/métodos , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/cirurgia , Células-Tronco/patologia , Animais , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transplante de Células-Tronco/métodos , Resultado do TratamentoRESUMO
Acute myocardial infarction (MI) is the leading cause of death worldwide. Exogenous delivery of nitric oxide (NO) to the infarcted myocardium has proven to be an effective strategy for treating MI due to the multiple physiological functions of NO. However, reperfusion of blood flow to the ischemic tissues is accompanied by the overproduction of toxic reactive oxygen species (ROS), which can further exacerbate tissue damage and compromise the therapeutic efficacy. Here, an injectable hydrogel is synthesized from the chitosan modified by boronate-protected diazeniumdiolate (CS-B-NO) that can release NO in response to ROS stimulation and thereby modulate ROS/NO disequilibrium after ischemia/reperfusion (I/R) injury. Furthermore, administration of CS-B-NO efficiently attenuated cardiac damage and adverse cardiac remodeling, promoted repair of the heart, and ameliorated cardiac function, unlike a hydrogel that only released NO, in a mouse model of myocardial I/R injury. Mechanistically, regulation of the ROS/NO balance activated the antioxidant defense system and protected against oxidative stress induced by I/R injury via adaptive regulation of the Nrf2-Keap1 pathway. Inflammation is then reduced by inhibition of the activation of NF-κB signaling. Collectively, these results show that this dual-function hydrogel may be a promising candidate for the protection of tissues and organs after I/R injury.
Assuntos
Traumatismo por Reperfusão Miocárdica , Animais , Hidrogéis , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Traumatismo por Reperfusão Miocárdica/induzido quimicamente , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Fator 2 Relacionado a NF-E2/metabolismo , Óxido Nítrico , Espécies Reativas de Oxigênio/metabolismoRESUMO
There is a lack in clinically-suitable vascular grafts. Biotubes, prepared using in vivo tissue engineering, show potential for vascular regeneration. However, their mechanical strength is typically poor. Inspired by architectural design of steel fiber reinforcement of concrete for tunnel construction, poly(ε-caprolactone) (PCL) fiber skeletons (PSs) were fabricated by melt-spinning and heat treatment. The PSs were subcutaneously embedded to induce the assembly of host cells and extracellular matrix to obtain PS-reinforced biotubes (PBs). Heat-treated medium-fiber-angle PB (hMPB) demonstrated superior performance when evaluated by in vitro mechanical testing and following implantation in rat abdominal artery replacement models. hMPBs were further evaluated in canine peripheral arterial replacement and sheep arteriovenous graft models. Overall, hMPB demonstrated appropriate mechanics, puncture resistance, rapid hemostasis, vascular regeneration, and long-term patency, without incidence of luminal expansion or intimal hyperplasia. These optimized hMPB properties show promise as an alternatives to autologous vessels in clinical applications.
RESUMO
The newly discovered human voltage-gated proton channel Hv1 is essential for proton transfer, which contains a voltage sensor domain (VSD) without a pore domain. We report here for the first time that Hv1 is specifically expressed in the highly metastatic human breast tumor tissues, but not in poorly metastatic breast cancer tissues, detected by immunohistochemistry. Meanwhile, real-time RT-PCR and immunocytochemistry showed that the expression levels of Hv1 have significant differences among breast cancer cell lines, MCF-7, MDA-MB-231, MDA-MB-468, MDA-MB-453, T-47D and SK-BR-3, in which Hv1 is expressed at a high level in highly metastatic human breast cancer cell line MDA-MB-231, but at a very low level in poorly metastatic human breast cancer cell line MCF-7. Inhibition of Hv1 expression in the highly metastatic MDA-MB-231 cells by small interfering RNA (siRNA) significantly decreases the invasion and migration of the cells. The intracellular pH of MDA-MB-231 cells down-regulated Hv1 expression by siRNA is obviously decreased compared with MDA-MB-231 with the scrambled siRNA. The expression of matrix metalloproteinase-2 and gelatinase activity in MDA-MB-231 cells suppressed Hv1 by siRNA were reduced. Our results strongly suggest that Hv1 regulates breast cancer intracellular pH and exacerbates the migratory ability of metastatic cells.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Canais Iônicos/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Feminino , Humanos , Canais Iônicos/genética , Invasividade Neoplásica , Metástase Neoplásica , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Interferente Pequeno/genéticaRESUMO
Cell labeling and tracking are becoming increasingly important in the fields of stem cell transplantation. To track the migration and distribution of the implanted cells is critical for understanding the beneficial effects of stem cell therapy. The aim of this study is to synthesize new superparamagnetic nanoparticles and investigate the feasibility of magnetic labeling of bone marrow mesenchymal stem cells (MSCs). Monodisperse hydrophobic magnetite (Fe3O4) nanoparticles were prepared through high temperature decomposition of Fe(acac)3 and a long-chain alcohol. The nanoparticles were further modified with a bipolar surfactant, 2,3-dimercaptosuccinic acid (DMSA) and then transformed into water-soluble iron oxide nanoparticles (WION). The magnetic particles showed uniform size (10 nm), high efficiency and stability in MSCs labeling. The labeled cells were cultured until passage 8, there is no reduction in magnetic tropism and the percentage of labeled cells. The results of MTT proliferation assay and flow cytometry analysis show that the WION are biocompatible. The labeling process does not cause cell death and apoptosis, and has no side effect on growth capacity of the cells. In conclusion, the successful and stable labeling of MSCs and the efficient magnetic tropism indicate that this WION can be used for tracking of MSCs in future MSCs-based stem cell therapy.
Assuntos
Magnetismo , Nanopartículas , Animais , Linhagem Celular , Proliferação de Células , Compostos Férricos/química , Citometria de Fluxo , Humanos , Camundongos , Difração de Pó , Succímero/química , Tensoativos/químicaRESUMO
A delipid extracorporeal lipoprotein filter (DELP) system has been used to treat patients with stroke and has shown favorable prognosis. However, the mechanism for the neuronal functional recovery remains unclear. This study aimed to investigate the neuronal histological assessment, and the levels of C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), and oxidized low-density lipoprotein (oxLDL) after ischemic stroke following DELP treatment. Hyperlipidemic rabbits underwent middle cerebral artery occlusion. After 30 min, the animals received an extracorporeal apheresis treatment with a DELP filter. Total cholesterol (TC), triglyceride, and low-density lipoprotein (LDL) of the plasma were measured. The levels of CRP, TNF-α, and oxLDL in brain tissue were also measured by enzyme-linked immunosorbent assay. Hematoxylin and eosin staining, cresyl violet staining, neuron-specific enolase (NSE) and glial fibrillary acidic protein immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed. DELP apheresis reduced TC and LDL by >30%. The number of neurons at day 7 (P < 0.01) and the integrated optical density of NSE at day 1 (P < 0.05) and day 7 (P < 0.01) were significantly increased in the DELP group. TUNEL-positive cells were significantly decreased (P < 0.05). Astrocytes were moderately activated, and this activation persisted up to 7 days. Gliosis was not found in the DELP group. After treatment, the level of CRP declined at day 1 (P < 0.05); TNF-α and oxLDL declined at day 7 (P < 0.05). DELP apheresis decreased neuronal apoptosis, reduced inflammatory markers and oxidative stress in cerebral ischemia, and improved neuronal survival.
Assuntos
Remoção de Componentes Sanguíneos/instrumentação , Isquemia Encefálica/metabolismo , Isquemia Encefálica/terapia , Hiperlipidemias/terapia , Lipoproteínas/isolamento & purificação , Neurônios/patologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Isquemia Encefálica/sangue , Isquemia Encefálica/patologia , Proteína C-Reativa/metabolismo , Sobrevivência Celular , Colesterol/sangue , Desenho de Equipamento , Hiperlipidemias/sangue , Hiperlipidemias/metabolismo , Hiperlipidemias/patologia , Lipoproteínas/sangue , Lipoproteínas/metabolismo , Lipoproteínas LDL/sangue , Lipoproteínas LDL/isolamento & purificação , Lipoproteínas LDL/metabolismo , Masculino , Neurônios/citologia , Neurônios/metabolismo , Coelhos , Triglicerídeos/sangue , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Nitric oxide (NO) is a short-lived signaling molecule that plays a pivotal role in cardiovascular system. Organic nitrates represent a class of NO-donating drugs for treating coronary artery diseases, acting through the vasodilation of systemic vasculature that often leads to adverse effects. Herein, we design a nitrate-functionalized patch, wherein the nitrate pharmacological functional groups are covalently bound to biodegradable polymers, thus transforming small-molecule drugs into therapeutic biomaterials. When implanted onto the myocardium, the patch releases NO locally through a stepwise biotransformation, and NO generation is remarkably enhanced in infarcted myocardium because of the ischemic microenvironment, which gives rise to mitochondrial-targeted cardioprotection as well as enhanced cardiac repair. The therapeutic efficacy is further confirmed in a clinically relevant porcine model of myocardial infarction. All these results support the translational potential of this functional patch for treating ischemic heart disease by therapeutic mechanisms different from conventional organic nitrate drugs.
Assuntos
Implantes de Medicamento/metabolismo , Infarto do Miocárdio/metabolismo , Nitratos/metabolismo , Óxidos de Nitrogênio/metabolismo , Animais , Cardiotônicos/metabolismo , Cardiotônicos/farmacologia , Modelos Animais de Doenças , Implantes de Medicamento/farmacologia , Coração/efeitos dos fármacos , Coração/fisiopatologia , Ativação de Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/prevenção & controle , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/prevenção & controle , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Células RAW 264.7 , Ratos Sprague-Dawley , Taxa de Sobrevida , SuínosRESUMO
The aim of the present study was to investigated the construction of polycaprolactone-lecithin (PCL-L) electrospun fibers as a novel scaffold material for a tissue-engineered ureter. The effect of bone marrow mesenchymal stem cells (BM-MSCs) on the neovascularization of the scaffolds and the viability of planted urothelial cells (UCs) on PCL-L were also studied. UCs were obtained from New Zealand rabbit bladders, cultured and then seeded onto the lumen of the tubular scaffolds before being subcutaneously transplanted into the space of nude mice. The cultured UCs showed vacuolar degeneration after 7 days of transplantation and they gradually degraded thereafter. To facilitate the regeneration of the tissue-engineered ureter and the survival of UCs in the implant, MSCs were seeded into the tubular grafts by rolling up the nanofibrous membrane, followed by the seeding of UCs. This facilitated the survival of the UCs, which formed several cellular layers after 30 days. The mean microvessel density was significantly increased in tissues seeded with MSCs. Cell-tracking experiments revealed that the transplanted MSCs did not integrate directly into capillaries for angiogenesis. Our results demonstrated that the PCL-L electrospun fibrous scaffold has a high potential for a tissue-engineered ureter especially when seeded with BM-MSCs, which enhanced angiogenesis.
Assuntos
Lecitinas , Transplante de Células-Tronco Mesenquimais , Poliésteres , Alicerces Teciduais/química , Transplantes , Ureter/cirurgia , Bexiga Urinária/transplante , Animais , Transplante de Medula Óssea , Sobrevivência de Enxerto , Nanofibras/química , Coelhos , Ratos , Ratos Nus , Bexiga Urinária/citologia , Urotélio/citologia , Urotélio/transplanteRESUMO
L-3,4-dihydroxyphenylalanine (L-DOPA) is currently the main drug used to treat Parkinson's disease (PD). However, long-term use of l-DOPA causes substantial side effects, and we hope to find a biological active ingredient that synergizes with a low-dose of l-DOPA to achieve the same therapeutic effect as that of a high-dose of l-DOPA. The natural product parthenolide (PTL) is the active ingredient in the medicinal plant feverfew (Tanacetum parthenium) and has antioxidant and anti-inflammatory properties. ACT001, a fumarate salt form of dimethylaminomicheliolide (DMAMCL), is a derivative of parthenolide and has comparable effects to those of PTL but exhibits higher stability in the plasma and is available at a lower cost. In our study, we used ACT001 in combination with l-DOPA to treat 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced Parkinson's disease in mice. Specifically, ACT001 significantly reduced motor dysfunction and dopaminergic neurodegeneration in MPTP-treated mice. Furthermore, ACT001 abolished MPTP-induced α-synuclein overexpression, astrocyte activation and interleukin-1ß (IL-1ß) production in the substantia nigra and striatum of the mouse brain. In addition, ACT001 increased the levels of the anti-apoptotic signalling molecule Bcl-2 and the pAkt/Akt ratio and reduced the levels of the pro-apoptotic signalling molecule Bax and the activation of Caspase3 in the substantia nigra and striatum. We found that the effects of the co-administration of ACT001 and l-DOPA (5â¯mg/kg) were equivalent to those of the administration of 8â¯mg/kg l-DOPA in MPTP-induced Parkinson's disease in mice. Then, this evidence suggests that l-DOPAâ¯+â¯ACT001 may be used for the treatment of PD.